1. Field
Embodiments relate to a current interrupting device that senses temperature variations to interrupt a current, and a secondary battery including such a current interrupting device.
2. Description of the Related Technology
With the trend of lightweight and highly functional portable wireless devices, such as video cameras, mobile phones, and portable computers, research is being actively carried out on secondary batteries functioning as driving power sources of the portable wireless devices. For example, second batteries can include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, the lithium secondary batteries may be rechargeable and adapted for miniaturization and high capacity. In addition, since the lithium secondary batteries typically have high operation voltages and high energy density per a unit weight, the lithium secondary batteries are widely used in high-end electronic devices.
Such a secondary battery may be formed by disposing a generating unit including a positive electrode plate, a negative electrode plate, and a separator, that is, an electrode assembly in a metal can, and by injecting electrolyte in the can and sealing the can. As such, the secondary battery sealed with the can may include an electrode terminal insulated from the can and disposed on the upper side, so that the electrode terminal functions as a pole, and the can functions as the opposite pole.
A secondary battery can include a battery safety device, such as a protecting circuit module (PCM) controlling the charge or discharge of the battery or a secondary protective device replacing the PCM, and the battery safety device may be disposed in a battery pack. Such battery safety devices are typically connected to a positive electrode and a negative electrode to interrupt a current when the temperature of a battery is increases excessively or when the voltage of the battery increases quickly by overdischarge or overcharge of the battery, thus preventing accidents such as explosion of the battery.